1. Field of the Invention
The present invention relates to devices that generate an alarm signal when conditions surrounding an invalid, infant, or child, or other person or a caretaker thereof, warrant it.
2. Background
Remote security monitoring systems in which a video camera is trained on a subject or area of concern and observed by a trained observer are known in the art. Also infant or child monitors that transmit audio to a portable receiver are available in the market. These devices, however, require constant attention in order to provide protection to the subject or area of concern, such as an infant or child.
Automated infant or child monitors have been proposed which, for example, monitor an infant's sleeping position to help prevent sudden infant or child death syndrome (SIDS). One approach, suggested in U.S. Pat. No. 5,864,291 uses a breathing-sensing strap around the infant's torso to detect breathing. Another (U.S. Pat. No. 5,638,824) suggests using an ultrasonic sensor and U.S. Pat. No. 5,914,660 position sensors for the same purpose. The automation in these types of monitors, however, provide little use for babies that are distressed for reasons other than a failure to breathe or sleep in an expected position. Also, the alarm signal may contain false positives and is of little help in diagnosing the cause of distress.
A monitored person's physical and emotional state may be determined by a computer for medical diagnostic purposes. For example, U.S. Pat. No. 5,617,855, hereby incorporated by reference as if fully set forth herein, describes a system that classifies characteristics of the face and voice along with electroencephalogram and other diagnostic data to help make diagnoses. The device is aimed at the fields of psychiatry and neurology. This and other such devices, however, are not designed for monitoring persons in their normal environments.
In still another application area, machines automatically detect an occupant's presence or specific features of the occupant for purposes of machine-authorization and authentication or convenience. To that end, some prior art systems employ biometric sensing, proximity detectors, radio frequency identification tags, or other devices.
EP 0716402B1 describes a method of detecting the number of people entering a train or other space using infrared sensors and fuzzy inference techniques. When the number of people is outside desired limits or unbalanced, the system can generate notices to that effect which may be linked to devices to correct the condition.
UK 2027312A describes a method of detecting the movement of fish using IR cameras generating a standard video signal.
U.S. Pat. No. 4,524,243 describes a system in which a user is required to activate a switch at specified intervals. Failure to do so results in the generation of an inactivity alarm.
U.S. Pat. No. 5,905,436 discloses a system in which the failure of various sensors in a home to be triggered results in the generation of a signal at a central monitoring station indicating such. The disclosure is directed at the supervision of an elderly person living at home.
UK 2179186A describes a system in which, if movement not detected at a pre-determined time, an alarm is triggered. A warning is given so that the user can reset the switch.
U.S. Pat. No. 6,002,994 discloses a system in which transmitters, placed at strategic locations in a house, are triggered whenever a person is present at the location of a sensor triggering the transmitter. Also, the system employs other inputs attached to devices and appliances that the user is expected to use. The system is trained to recognize normal patterns of use. The transmitters transmit a signal to a central monitor if the normal pattern is not followed.
In this reference, physiological measurements may include the user's blood pressure, heart rate, body temperature, body weight and blood glucose level. Non-physiological measurements may include room temperature, ammonia from spilled urine, methane from spoiling food, a presence of smoke, frequency of electrical usage, frequency of water usage, temperature of water flowing from a tap, the user's movement within the selected environment as indicated by motion sensors, and use of appliances including a toilet, telephone, stove, microwave oven, toaster, oven, refrigerator, freezer, dishwasher, bath, shower, garbage disposal means, clothes washer, clothes drier, mail box, door and vehicle.
Machine identification of faces is a technology that is well-developed. In GB 2343945A for a system for photographing or recognizing a Face, a controller identifies moving faces in a scene and tracks them to permit image capture sufficient to identify the face or distinctive features thereof. For example, the system could sound an alarm upon recognizing a pulled-down cap or face mask in a jewelry store security system.
There remains a need in the present art for a system that monitors persons requiring supervision to be more robust, capable of responding to more subtle cues and provide more informative information to supervisors.